1 files changed, 188 insertions, 0 deletions
diff --git a/src/speedymalloc.c b/src/speedymalloc.c
new file mode 100644
index 0000000..4d10cb6
--- /dev/null
+++ b/src/speedymalloc.c
@@ -0,0 +1,188 @@
+#include <assert.h>
+#include <errno.h>
+#include <stddef.h> /* NULL, size_t */
+#include <stdint.h> /* uintptr_t */
+#include <stdio.h> /* fprintf */
+#include <stdlib.h> /* exit */
+#include <string.h> /* memset */
+#include <sys/mman.h> /* mmap */
+
+#define MIN_ALIGNMENT 16
+
+#ifdef DONTNEED
+#define MY_MADVISE_FREE MADV_DONTNEED
+#else
+#define MY_MADVISE_FREE MADV_FREE
+#endif
+
+#ifndef MEMSIZE
+#define MEMSIZE 1024*4*1024*1024l
+#endif
+
+#ifndef NO_WILLNEED
+#define WILLNEED_SIZE 32 * 1024 * 1024
+#endif
+
+// sizeof(tls_t) == 4096
+#define CACHE_BINS 511
+// max cached object: 511 * 64 - 1 = 32703
+#define CACHE_BIN_SEPERATION 64
+
+#define unlikely(x)     __builtin_expect((x),0)
+#define PAGE_SIZE 4096
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct chunk {
+	size_t size; // Size header field for internal use
+	struct chunk* next;
+} chunk_t;
+
+static inline chunk_t* ptr2chunk(void* ptr) {
+	return (chunk_t*)((uintptr_t)ptr - sizeof(size_t));
+}
+
+static inline void* chunk2ptr (chunk_t* chunk) {
+	return (void*)((uintptr_t)chunk + sizeof(size_t));
+}
+
+static inline uintptr_t alignup (uintptr_t ptr, size_t alignment) {
+	size_t mask = alignment -1;
+	return (ptr + mask) & ~mask;
+}
+
+typedef struct TLStates {
+	uintptr_t ptr;
+	chunk_t* bins[CACHE_BINS];
+} tls_t;
+
+__thread tls_t* tls;
+__thread uintptr_t next_willneed;
+
+static inline int size2bin(size_t size) {
+	assert(size > 0 && size < CACHE_BINS * CACHE_BIN_SEPERATION);
+	return (size - 1) / CACHE_BIN_SEPERATION;
+}
+
+static inline size_t bin2size(int bin) {
+	assert(bin >= 0 && bin < CACHE_BINS);
+	return (bin + 1) * CACHE_BIN_SEPERATION;
+}
+
+static void init_tls(void) {
+	void *mem = mmap(NULL, MEMSIZE, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
+	if (mem == MAP_FAILED) {
+		perror("mmap");
+		exit(1);
+	}
+	tls = (tls_t*)mem;
+
+	tls->ptr = ((uintptr_t)tls) + sizeof(tls_t);
+#ifndef NO_WILLNEED
+	next_willneed = tls->ptr;
+#endif
+}
+
+static void* bump_alloc(size_t size) {
+	// allocate size header
+	tls->ptr += sizeof(size_t);
+
+	// align ptr
+	tls->ptr = alignup(tls->ptr, MIN_ALIGNMENT);
+
+#ifndef NO_WILLNEED
+	if(unlikely(tls->ptr >= next_willneed)) {
+		madvise((void*)next_willneed, WILLNEED_SIZE, MADV_WILLNEED);
+		next_willneed += WILLNEED_SIZE;
+	}
+#endif
+
+	void* ptr = (void*)tls->ptr;
+	ptr2chunk(ptr)->size = size;
+	tls->ptr += size;
+
+	return ptr;
+}
+
+void* malloc(size_t size) {
+	if (unlikely(tls == NULL)) {
+		init_tls();
+	}
+
+	// cached sizes
+	if (size < CACHE_BINS * CACHE_BIN_SEPERATION) {
+		int bin = size2bin(size);
+		if (tls->bins[bin] != NULL) {
+			chunk_t* chunk = tls->bins[bin];
+			// remove first chunk from list
+			tls->bins[bin] = chunk->next;
+			return chunk2ptr(chunk);
+		}
+		return bump_alloc(bin2size(bin));
+	}
+
+	return bump_alloc(size);
+}
+
+void free(void* ptr) {
+	if (unlikely(tls == NULL)) {
+		init_tls();
+	}
+
+	if (ptr == NULL) {
+		return;
+	}
+
+	chunk_t* chunk = ptr2chunk(ptr);
+
+	if (chunk->size < CACHE_BINS * CACHE_BIN_SEPERATION) {
+		int bin = size2bin(chunk->size);
+		chunk->next = tls->bins[bin];
+		tls->bins[bin] = chunk;
+	}
+#ifndef NO_FREE
+	else {
+		size_t size = chunk->size;
+		size -= ((uintptr_t)ptr % PAGE_SIZE); // size without part before a page boundry
+		size -= size % PAGE_SIZE; // size without part after a page boundry
+
+		void* page_start = (void*)alignup((uintptr_t)ptr, PAGE_SIZE);
+		//fprintf(stderr, "ptr: %p, s: %ux, pages: %ux, page_ptr: %p\n",
+		//        ptr, chunk->size, size, page_start);
+		madvise(page_start, size, MY_MADVISE_FREE);
+	}
+#endif
+}
+
+void* memalign(size_t alignment, size_t size) {
+	/* if not power of two */
+	if (!((alignment != 0) && !(alignment & (alignment - 1)))) {
+		return NULL;
+	}
+
+	if (unlikely(tls == NULL)) {
+		init_tls();
+	}
+
+	// allocate size header
+	tls->ptr += sizeof(size_t);
+
+	tls->ptr = alignup(tls->ptr, alignment);
+
+	void* ptr = (void*)tls->ptr;
+	ptr2chunk(ptr)->size = size;
+	tls->ptr += size;
+
+	return ptr;
+}
+
+void malloc_stats() {
+	fprintf(stderr, "speedymalloc allocator by muhq\n");
+	fprintf(stderr, "Memsize: %zu, start address: %p, bump pointer %p\n", MEMSIZE, tls, tls->ptr);
+}
+
+#ifdef __cplusplus
+}
+#endif